#include "blaswrap.h"
#include "f2c.h"

/* Subroutine */ int claqsp_(char *uplo, integer *n, complex *ap, real *s, 
	real *scond, real *amax, char *equed)
{
/*  -- LAPACK auxiliary routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       February 29, 1992   


    Purpose   
    =======   

    CLAQSP equilibrates a symmetric matrix A using the scaling factors   
    in the vector S.   

    Arguments   
    =========   

    UPLO    (input) CHARACTER*1   
            Specifies whether the upper or lower triangular part of the   
            symmetric matrix A is stored.   
            = 'U':  Upper triangular   
            = 'L':  Lower triangular   

    N       (input) INTEGER   
            The order of the matrix A.  N >= 0.   

    AP      (input/output) COMPLEX array, dimension (N*(N+1)/2)   
            On entry, the upper or lower triangle of the symmetric matrix   
            A, packed columnwise in a linear array.  The j-th column of A   
            is stored in the array AP as follows:   
            if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;   
            if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.   

            On exit, the equilibrated matrix:  diag(S) * A * diag(S), in   
            the same storage format as A.   

    S       (input) REAL array, dimension (N)   
            The scale factors for A.   

    SCOND   (input) REAL   
            Ratio of the smallest S(i) to the largest S(i).   

    AMAX    (input) REAL   
            Absolute value of largest matrix entry.   

    EQUED   (output) CHARACTER*1   
            Specifies whether or not equilibration was done.   
            = 'N':  No equilibration.   
            = 'Y':  Equilibration was done, i.e., A has been replaced by   
                    diag(S) * A * diag(S).   

    Internal Parameters   
    ===================   

    THRESH is a threshold value used to decide if scaling should be done   
    based on the ratio of the scaling factors.  If SCOND < THRESH,   
    scaling is done.   

    LARGE and SMALL are threshold values used to decide if scaling should   
    be done based on the absolute size of the largest matrix element.   
    If AMAX > LARGE or AMAX < SMALL, scaling is done.   

    =====================================================================   


       Quick return if possible   

       Parameter adjustments */
    /* System generated locals */
    integer i__1, i__2, i__3, i__4;
    real r__1;
    complex q__1;
    /* Local variables */
    static integer i__, j;
    static real large;
    extern logical lsame_(char *, char *);
    static real small;
    static integer jc;
    static real cj;
    extern doublereal slamch_(char *);

    --s;
    --ap;

    /* Function Body */
    if (*n <= 0) {
	*(unsigned char *)equed = 'N';
	return 0;
    }

/*     Initialize LARGE and SMALL. */

    small = slamch_("Safe minimum") / slamch_("Precision");
    large = 1.f / small;

    if (*scond >= .1f && *amax >= small && *amax <= large) {

/*        No equilibration */

	*(unsigned char *)equed = 'N';
    } else {

/*        Replace A by diag(S) * A * diag(S). */

	if (lsame_(uplo, "U")) {

/*           Upper triangle of A is stored. */

	    jc = 1;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		cj = s[j];
		i__2 = j;
		for (i__ = 1; i__ <= i__2; ++i__) {
		    i__3 = jc + i__ - 1;
		    r__1 = cj * s[i__];
		    i__4 = jc + i__ - 1;
		    q__1.r = r__1 * ap[i__4].r, q__1.i = r__1 * ap[i__4].i;
		    ap[i__3].r = q__1.r, ap[i__3].i = q__1.i;
/* L10: */
		}
		jc += j;
/* L20: */
	    }
	} else {

/*           Lower triangle of A is stored. */

	    jc = 1;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		cj = s[j];
		i__2 = *n;
		for (i__ = j; i__ <= i__2; ++i__) {
		    i__3 = jc + i__ - j;
		    r__1 = cj * s[i__];
		    i__4 = jc + i__ - j;
		    q__1.r = r__1 * ap[i__4].r, q__1.i = r__1 * ap[i__4].i;
		    ap[i__3].r = q__1.r, ap[i__3].i = q__1.i;
/* L30: */
		}
		jc = jc + *n - j + 1;
/* L40: */
	    }
	}
	*(unsigned char *)equed = 'Y';
    }

    return 0;

/*     End of CLAQSP */

} /* claqsp_ */

